From January 21-23, 1966, the open-minded from all over converged at San Francisco's Longshoremen's Hall for a continuous loop of sensory overload that was advertised, promoted and managed like one might push a county fair. The Festival gave the word 'experience' a whole new meaning as music, readings, light shows, dancing, dress up, and dress optional took over briefly in the Bay area. Bill Graham, who was just beginning to gain steam as a promoter, signed on as de facto organizer and almost lost his mind over the reigning chaos of the first 24 hours. The Trips Festival, however, proved to be Graham's 'initiation rite' into the emerging world of the dance concert which then became the rock concert.

When the Avalon Ballroom and Bill Graham's Fillmore Auditorium began to hold weekly dance concerts, Wilson was called upon to design the posters. He created psychedelic posters from February 1966 to May 1967, when disputes over money severed his connection with Graham. Wilson pioneered the psychedelic rock poster. Intended for a particular audience, "one that was tuned in to the psychedelic experience," his art, and especially the exaggerated freehand lettering, emerged from Wilson's own involvement with that experience and the psychedelic art of light shows.